Can I add Html Text formatting in my Photoshop or ImageReady layout?

Yes.

Follow these few steps: (Both Photoshop & ImageReady)
A. Select the Slice Select Tool, then double click the Slice you want to apply html text formatting.
B. Then from the 'Slice Options' dialog, change the 'Slice Type' feature from 'Image' to 'No Image'.
C. A 'Text Displayed in Cell' field appears to allow for normal text or html formatted text.

Is it possible to use my operating systems Color Picker other than the default Photoshop Color Picker?

Yes.

Hit Ctrl+K (Mac:Command+K) to open the Preferences.
In the 'General' area, from the second drop down option captioned 'Color Picker', select your operating system, Windows/Apple.

(You will obviously only see the your OS option and not both)

How do I create a border around my image?

A. Create a new layer. (Shift+Ctrl+N / Mac: Shift+Command+N)
B.Drag that new layer to the top of the Layers Palette stacking order.
C.Ctrl+A /Mac:Command+A to activate a selection surrounding your entire document.
D.Go 'Edit/Stroke' menu command.
E. Set your desired Stroke width, color, location, blending & opacity options.

Then OK.

How can I auto center a layer on drag and drop from one document to another?

Hold the Shift key as you drag from the base document to the target document will automatically center align it.

How do I locate the hidden Tools on the Toolbar? Grouped Tools have a small triangle in the lower right of the head tool for that particular group.

Click and hold on the head tool that has the triangle icon and the flyout group/menu appears.

Toggle to one of the grouped Tools, hold the Shift key + that main Tools key shortcut.
For eample, to cycle through the Shape Tools (U) (Rectangle, Rounded Rectangle, Ellipse, Polygonal, Line, Custom) hold the Shift Key + U.

To find out what the active Tools keyboard shortcut is, it's the Letter to the far right of the tool title.

For tools that don't have a flyout menu and you whant instant access to it's keyboard shortcut turn on the 'Show Tool Tips' Option via 'Edit/Preferences/General' menu command. That way everytime you mouse over a Tool the corresponding keyboard shortcut will pop up in an info caption.